The present invention relates to alphanumeric keyboards for hand-held computers, word processors, mobile telephones and other electronic devices.
The ability to decrease the size of portable computers, word processors, and similar devices has been limited to an important extent by the space needed for a workable keyboard. This problem is also relevant for the development of portable telephones with word processors and/or Internet access features. Traditional keyboard arrangements (e.g., QWERTY) can be inconvenient to use if they are made smaller than the standard size.
One space-saving solution for some portable telephones has been to use the regular number buttons to type or punch in letters that are commonly associated with those numbers on the telephone dial pad. The user presses a particular number key once, twice or more times to select one of the letters. An advantage of this solution is that it uses an association of letters with numbers and key locations that is familiar to potential users. The main problem is that users must make a larger number of key strokes than they otherwise would have to make on a standard typewriter keyboard.
Some portable telephones have employed a generally flat button that can be used for up to four functions, with each function corresponding to one edge of the button. The user selects the desired functions by pressing down near the appropriate edge. However, most telephones that have this feature typically provide only one such button, and its function usually is limited to scrolling or selecting menu options. Such buttons have not been used for typing alphanumeric characters. This may be because such buttons do not provide a significant space saving advantage over regular buttons, since the space needed for one flat, four-function button would be about the same as that needed for four regular buttons if the amount of surface area available for selecting each function were to be kept the same in both arrangements.
A solution that places several functions on one key without the need to make more than one keystroke per function is disclosed in U.S. Pat. No. 5,841,374. However, operation requires the use of all fingers, which means that the user must place the device on a flat surface to use it, and therefore may not hold it in his/her hands.
Ojima U.S. Pat. No. 4,029,915 discloses a keyboard consisting of a single row of resiliently biased keys, each adapted to be tilted in one of four directions by the user""s finger tip for inputting information. The keys have a recessed top with a raised edge in a preferred embodiment or central projection sloping down to the respective edges of the keys in an alternative embodiment. The user""s fingers are xe2x80x9cbasedxe2x80x9d on the keys and effect up, down, left and right movements. Simple keyboard operations require awkward finger movements.
Lin U.S. Pat. No. 5,528,235 discloses a keyboard array with rows of resiliently biased keys having five facets, four along the edges and the fifth at the center. The facets along the edges slope down to the fifth, recessed central facet. The user""s fingers are based on the keys and effect up, down, left, right movements for inputting the desired signals. It has the same drawbacks as Ojima.
This space saving alphanumeric keyboard attempts to reconcile the tradeoff between size and efficiency for small hand-held devices such as xe2x80x9cpalm-topxe2x80x9d computers and mobile telephones, or even for non hand-held devices for which a small keyboard is desired. It does this by placing several characters on each key member, but without the need to make more than one keystroke per character. It employs a small number of multi-faceted key members, each of which may be easily and rapidly manipulated in a plurality of different directions, and makes use of spaces between clusters of keys as xe2x80x9cbasesxe2x80x9d for the operator""s thumbs or other fingers.
According to the invention, there is provided an array of key members for inputting data or signals to an electronic device. Each key member has a convex outer surface including a plurality of outwardly converging facets. Each facet has corresponding alphanumerical characters or other indicia and is associated with a single switching means corresponding to alphanumerical characters or other indicia. Means responsive to the application of pressure on each of said facets actuates a corresponding one of the switching means. The array of key members comprises two or more aligned key members intersecting with two or more other aligned key members at at least one intersection. A finger base is located at the at least one intersection between adjacent key members and a single facet of the adjacent key members are located at each corner of the intersection.
Such a key member array advantageously provides finger bases at intersections between alignments of key members with direct access to the facets at the intersection, thereby improving ease of operation and overall ergonomy.
The features and advantages of the invention will become more apparent from the following description given by way of example with reference to the accompanying drawings.